The singer-turned-director's film is about Wallis Simpson, the American divorcee who Edward VIII abdicated the throne for, and she is keen to make sure all of the historical details are completely accurate.
Madonna has spoken to Prince Edward, Princess Michael of Kent and the Duke and Duchess of Gloucester, as well as a number of Buckingham Palace staff and top historians, reports The Sun.
A source told the newspaper: 'The entire Royal Family were contacted and asked if they would like to meet Madonna and production staff - and many took up the opportunity.
'Some senior figures turned it down. But others, including Princess Michael of Kent, Prince Edward and the Gloucesters, jumped at the chance.'